text: /*
   * $Id: ct82c710.c,v 1.11 2001/09/25 10:12:07 vojtech Exp $
   *
   *  Copyright (c) 1999-2001 Vojtech Pavlik
   */
  
  /*
   *  82C710 C&T mouse port chip driver for Linux
   */
  
  /*
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; either version 2 of the License, or 
   * (at your option) any later version.
   * 
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   * 
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
   * 
   * Should you need to contact me, the author, you can do so either by
   * e-mail - mail your message to <vojtech@ucw.cz>, or by paper mail:
   * Vojtech Pavlik, Simunkova 1594, Prague 8, 182 00 Czech Republic
   */
  
  #include <linux/delay.h>
  #include <linux/module.h>
  #include <linux/ioport.h>
  #include <linux/config.h>
  #include <linux/init.h>
  #include <linux/interrupt.h>
  #include <linux/serio.h>
  #include <linux/errno.h>
  
  #include <asm/io.h>
  
  MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
  MODULE_DESCRIPTION("82C710 C&T mouse port chip driver");
  MODULE_LICENSE("GPL");
  
  static char ct82c710_name[] = "C&T 82c710 mouse port";
  static char ct82c710_phys[16];
  
  /*
   * ct82c710 interface
   */
  
  #define CT82C710_DEV_IDLE     0x01		/* Device Idle */
  #define CT82C710_RX_FULL      0x02		/* Device Char received */
  #define CT82C710_TX_IDLE      0x04		/* Device XMIT Idle */
  #define CT82C710_RESET        0x08		/* Device Reset */
  #define CT82C710_INTS_ON      0x10		/* Device Interrupt On */
  #define CT82C710_ERROR_FLAG   0x20		/* Device Error */
  #define CT82C710_CLEAR        0x40		/* Device Clear */
  #define CT82C710_ENABLE       0x80		/* Device Enable */
  
  #define CT82C710_IRQ          12
  
  static int ct82c710_data;
  static int ct82c710_status;
  
  static irqreturn_t ct82c710_interrupt(int cpl, void *dev_id, struct pt_regs * regs);
  
  /*
   * Wait for device to send output char and flush any input char.
   */
  
  static int ct82c170_wait(void)
  {
  	int timeout = 60000;
  
  	while ((inb(ct82c710_status) & (CT82C710_RX_FULL | CT82C710_TX_IDLE | CT82C710_DEV_IDLE))
  		       != (CT82C710_DEV_IDLE | CT82C710_TX_IDLE) && timeout) {
  
  		if (inb_p(ct82c710_status) & CT82C710_RX_FULL) inb_p(ct82c710_data);
  
  		udelay(1);
  		timeout--;
  	}
  
  	return !timeout;
  }
  
  static void ct82c710_close(struct serio *serio)
  {
  	if (ct82c170_wait())
  		printk(KERN_WARNING "ct82c710.c: Device busy in close()\n");
  
  	outb_p(inb_p(ct82c710_status) & ~(CT82C710_ENABLE | CT82C710_INTS_ON), ct82c710_status);
  
  	if (ct82c170_wait())
  		printk(KERN_WARNING "ct82c710.c: Device busy in close()\n");
  
  	free_irq(CT82C710_IRQ, NULL);
  }
  
  static int ct82c710_open(struct serio *serio)
  {
  	unsigned char status;
  
  	if (request_irq(CT82C710_IRQ, ct82c710_interrupt, 0, "ct82c710", NULL))
  		return -1;
  
  	status = inb_p(ct82c710_status);
  
  	status |= (CT82C710_ENABLE | CT82C710_RESET);
  	outb_p(status, ct82c710_status);
  
  	status &= ~(CT82C710_RESET);
  	outb_p(status, ct82c710_status);
  
  	status |= CT82C710_INTS_ON;
  	outb_p(status, ct82c710_status);	/* Enable interrupts */
  
  	while (ct82c170_wait()) {
  		printk(KERN_ERR "ct82c710: Device busy in open()\n");
  		status &= ~(CT82C710_ENABLE | CT82C710_INTS_ON);
  		outb_p(status, ct82c710_status);
  		free_irq(CT82C710_IRQ, NULL);
  		return -1;
  	}
  
  	return 0;
  }
  
  /*
   * Write to the 82C710 mouse device.
   */
  
  static int ct82c710_write(struct serio *port, unsigned char c)
  {
  	if (ct82c170_wait()) return -1;
  	outb_p(c, ct82c710_data);
  	return 0;
  }
  
  static struct serio ct82c710_port =
  {
  	.type	= SERIO_8042,
  	.name	= ct82c710_name,
  	.phys	= ct82c710_phys,
  	.write	= ct82c710_write,
  	.open	= ct82c710_open,
  	.close	= ct82c710_close,
  };
  
  /*
   * Interrupt handler for the 82C710 mouse port. A character
   * is waiting in the 82C710.
   */
  
  static irqreturn_t ct82c710_interrupt(int cpl, void *dev_id, struct pt_regs * regs)
  {
  	return serio_interrupt(&ct82c710_port, inb(ct82c710_data), 0, regs);
  }
  
  /*
   * See if we can find a 82C710 device. Read mouse address.
   */
  
  static int __init ct82c710_probe(void)
  {
  	outb_p(0x55, 0x2fa);				/* Any value except 9, ff or 36 */
  	outb_p(0xaa, 0x3fa);				/* Inverse of 55 */
  	outb_p(0x36, 0x3fa);				/* Address the chip */
  	outb_p(0xe4, 0x3fa);				/* 390/4; 390 = config address */
  	outb_p(0x1b, 0x2fa);				/* Inverse of e4 */
  	outb_p(0x0f, 0x390);				/* Write index */
  	if (inb_p(0x391) != 0xe4)			/* Config address found? */
  		return -1;				/* No: no 82C710 here */
  
  	outb_p(0x0d, 0x390);				/* Write index */
  	ct82c710_data = inb_p(0x391) << 2;		/* Get mouse I/O address */
  	ct82c710_status = ct82c710_data + 1;
  	outb_p(0x0f, 0x390);
  	outb_p(0x0f, 0x391);				/* Close config mode */
  
  	return 0;
  }
  
  int __init ct82c710_init(void)
  {
  	if (ct82c710_probe())
  		return -ENODEV;
  
  	if (request_region(ct82c710_data, 2, "ct82c710"))
  		return -EBUSY;
  
  	sprintf(ct82c710_phys, "isa%04x/serio0", ct82c710_data);
  
  	serio_register_port(&ct82c710_port);
  
  	printk(KERN_INFO "serio: C&T 82c710 mouse port at %#x irq %d\n",
  		ct82c710_data, CT82C710_IRQ);
  
  	return 0;
  }
  
  void __exit ct82c710_exit(void)
  {
  	serio_unregister_port(&ct82c710_port);
  	release_region(ct82c710_data, 2);
  }
  
  module_init(ct82c710_init);
  module_exit(ct82c710_exit);
  